Eating weeds like dandelions and fiddlehead ferns wasn’t always an accepted practice. Before these wild plants became staples at farmers’ markets across the country they were overlooked at best and considered inedible pests at worst.

But modern chefs are known for pushing culinary boundaries and so it should come as no surprise that some of the latest ingredients on restaurant menus are invasive species that were once considered off-limits.

Invasive species, whether they’re plants or animals, are non-native organisms that invade an area and threaten other wildlife. Common invasive plants include English Ivy and Honeysuckle.

Chef Bun Lai, the owner of Miya’s Sushi in New Haven, Connecticut has decided to include some of the most unusual invasive species on his menu.

Some of the “pests” he offers include, Asian shore crabs and Japanese knotweed, which is listed as one of the world’s 100 most invasive species. The Chef says the weed tastes crunchy, juicy and tart — like a granny smith apple.

Bun Lai has intentionally created an environmentally aware menu, which helped him garner praise as one of the most sustainable restaurants in the US from Fish2Fork, a restaurant guide for dining spots with sustainably caught seafood.

“My menu hopes to inspire conversation and thereby become a platform for environmental awareness and activism,” Bun Lai said.

In tropical locales, chefs have started serving lionfish, a striped fish with venomous dorsal fins. Lionfish invade coral reefs, fearlessly eat smaller fish and can kill 74% of the fish that naturally inhabit the reef, according to Food and Water Watch.